Bounty hunters... you may not feel you need them (being the scum that they are), but they do tend to get the job done when necessary. In the case of X-Wing, that generally means shooting holes in the enemy's ships. As the newest faction, the Scum & Villainy group doesn't have a lot of options, but the next wave of releases from Fantasy Flight Games will give them a few more. One of them is the YT-666, a set that has a preview posted up for you to look at.
For Star Wars fans, the most famous YT-666 would be the Hound's Tooth, flown by the bounty hunter Bossk. With this expansion, you get two different ways to play Bossk on the table. You can either have him be the pilot of a YT-666 (and specifically the Hound's Tooth with a certain bonus I'll get to in a little bit), or you can have him as a crew member. When the pilot, he lets you trade a Critical Hit for two regular Hits. That's pretty handy for busting through shields on enemy ships. When a crew member, Bossk is there to help out when you miss, since if you do, you get a stress token (bad), a focus token (good), and a target lock on your previous target (also good). But what about flying the Hound's Tooth, itself? Well, that gives you something pretty unique in X-Wing. If you buy this 6-point upgrade, then when your ship is destroyed, you get to deploy a Z-95 Headhunter, the Nashtah Pup, and have your pilot skill and ability transfer over to it. So your pilot can live to fight on a bit longer.